CORNISH: So I always explain this to people as eBay but for illegal things. How does it work?

KASTE: Yeah, that's pretty much it. They are not selling the things themselves. They're providing a space online where people can go to buy illegal goods. And the way it works, the way it becomes untraceable to the authorities is it goes through something called the Tor network, which is sort of a hopscotching system that covers your tracks in terms of your IP address when you make these connections.

But when you look at it on the screen, it just looks like an eBay site. In fact, there's ratings. There's reviews. And you know something about the kind of past customer experiences people have had with certain vendors. But the vendors are selling straight to purchasers, and the people running the website take a cut.

CORNISH: But there is a level of anonymity, right? And this is, as you said, balanced between these servers and these sites like Tor. So how did law enforcement catch up to AlphaBay?

KASTE: It looks like they screwed up. One fellow in particular that they focused on here who was thought to be the founder. And he at some point included his real Hotmail address in a couple of sort of routine housekeeping emails to users. They traced that back to him, found it was a Canadian, a 26-year-old Canadian who is now living in Thailand and apparently living the high life.

CORNISH: How high? I mean, how - what was his net worth?

KASTE: Well, you get a sense of just how good things were going for Alexandre Cazes, which is his name, by looking at the stuff that they are confiscating from him in the court documents - a Lamborghini, real estate, bank accounts in places like Cyprus and Liechtenstein. And then there's the cryptocurrency - the Bitcoin, the Ethereum. We kind of added all that up from the documents. Looks like he had at least $8 million in these sort of digital currencies. That's kind of a sign of the times, too, that these court documents the feds are talking about, these long strings of numbers as the ID for the currency they're confiscating. We're in a new era here. It's not just bank account numbers. It's Bitcoin addresses.

CORNISH: So what happened to this founder of AlphaBay?

KASTE: Well, he is dead. They raided his operation and arrested him earlier this month, about two weeks ago. And then now we find out a couple of days ago he died apparently in his jail cell in Thailand still waiting for some kind of extradition process. We're told that he committed suicide, that he hanged himself with a towel. But there's a lot we don't know yet about how he died and why.

CORNISH: I feel like these online dark web bazaars are a bit of a hydra. Like, you capture one, you shut down one, another one pops up in its place. I mean, isn't that what's going to happen here?

KASTE: Yeah. I mean, you know, we went through this three or four years ago with Silk Road. Do you remember - you might remember the name of that particular dark web marketplace that was shut down, equally kind of heralded by the authorities. That was quickly replaced by groups like AlphaBay. AlphaBay is even bigger than Silk Road. Some people say it was about 10 times bigger - millions of dollars going through there, maybe a million dollars a day. And, you know, just right now I looked online, and there's kind of a rating system. And there's several other dark web marketplaces you could go to.

The thing about AlphaBay, though, is it had a good reputation. People liked the service they were getting. Some of these other places you're not sure what you're getting. In fact, in one case, there's another website, another dark web marketplace called Hansa Market in Europe. A lot of people went there to buy their illegal goods. Turns out that has been quietly seized and run by the Dutch police for the last few weeks, so they have been doing business with the police. So for a while, at least, this market will be disrupted. There'll be a sense of insecurity.